Theresa May's Brexit plans were in disarray tonight after the Commons rejected her agreement with the European Union by 149 votes.
The emphatic 391-242 vote loss for the Prime Minister, following on from the first Meaningful Vote two months ago, means the UK is 17 days from leaving the EU with no prospect of any deal being approved by Parliament.
And Mrs May's plight was spelled out by one of her own MPs, Charles Walker, vice chairman of the 1922 Committee of backbench Tories, who said defeat in tonight's vote would lead to a general election "as sure as night follows day".
Giving a statement after the result was announced, the PM confirmed that MPs will tomorrow vote on whether to leave the EU without a deal and on Thursday about whether to extend Article 50 and delay Brexit.
She said: "But let me be clear. Voting against leaving without a deal and for an extension does not solve the problems we face. The EU will want to know what use we mean to make of such an extension.
"This House will have to answer that question. Does it wish to revoke Article 50? Does it want to hold a second referendum? Or does it want to leave with a deal but not this deal?
"These are unenviable choices, but thanks to the decision the House has made this evening they must now be faced."
Earlier, Mrs May's hopes of securing House of Commons approval for her Brexit deal suffered a shattering blow as Tory eurosceptics said they would not back it and her DUP allies said they would vote against.
A so-called Star Chamber convened by the Leave-backing European Research Group found that agreements reached by the Prime Minister in 11th-hour talks in Strasbourg do not deliver the legally-binding changes the Commons has demanded.
And the Democratic Unionist Party - which props up Mrs May's minority administration in the Commons - said its 10 MPs would vote against the latest deal as "sufficient progress has not been achieved at this time".
Their judgment came after Attorney General Geoffrey Cox told MPs that changes secured by Mrs May "reduce the risk" that the UK could be trapped indefinitely in the backstop, but do not remove it altogether.
The Prime Minister, battling a croaky voice and with husband Philip watching from the Commons gallery, warned MPs that "Brexit could be lost" if her deal was rejected again by MPs.
She said it was "absolutely imperative" that Parliament should deliver on the decision made by voters in the 2016 referendum.
And she warned: "Tonight, members of this House are faced with a very clear choice. Support this deal, in which case we leave the EU with a deal, or risk no-deal or no Brexit. These are the options."
Mr Cox's advice was issued the morning after Mrs May's dash to Strasbourg to finalise a deal with European Commission president Jean-Claude Juncker which she said would reassure MPs that the backstop arrangements to avoid a hard border in Ireland after Brexit will not become permanent.
The pair agreed a "joint instrument" setting out the legally-binding nature of their promises to seek alternative arrangements to avoid the need for a backstop, as well as a "supplement" to November's Political Declaration making clear that they will seek swiftly to seal a deal on their new trade and security relationship.
Alongside these documents was a "unilateral declaration by the UK" which sets out "sovereign action" by which Britain could seek to have the backstop removed if talks break down.
In a statement to the Commons, Mrs May said she had "fought hard" to persuade the EU to accept a time-limit, a unilateral exit mechanism or alternative arrangements for the backstop.
But she told MPs: "Ultimately you have to practise the art of the possible. I am certain we have secured the very best changes that were available."